The present invention relates to a capo device for varying the resonant length of tensioned strings on a stringed musical instrument, such as a dobro.
A dobro is similar in appearance to a guitar, and includes a hollow body portion with a metallic acoustic panel, an elongated neck which terminates in a tuning head, and six tensioned strings. However, dobro strings are formed of a heavier gauge wire than the strings of a guitar and are substantially less flexible. In addition, the strings of a dobro are positioned well above the fretboard on the neck of the dobro so that the distance between the dobro string and the fretboard is much greater on a dobro than on a guitar. In addition, the neck of the dobro is wider than the neck of a guitar. A dobro is held in a generally flat position across the lap of the player so that the neck and strings are horizontal, approximately perpendicular to the player's body.
Unlike a guitar player, a dobro player does not finger the strings to form a desired chord, but dampens or compresses the strings with a bar at the selected position across a fret with one hand while strumming or plucking the strings with the other hand.
Capos are sometimes used with guitars. A “capo” is a device that shortens the strings uniformly to facilitate a change of key from the major chord to which the guitar is initially tuned at the tuning head. For a number of reasons, including the difference in strings, height of the strings above the fretboard, and the wider neck of the dobro, capos used with guitars are not useful with dobros.
There have been some suggestions in the prior art for capo designs to be used with dobros. However, prior art capos suggested for use with dobros are generally difficult to quickly change with one hand while playing.